Anadara inaequivalvis ( Bruguière, 1789 )

Tudu, Prasad Chandra, Yennawar, Prasanna & Mohapatra, Anil, 2019, First report of two ark shells, Anadara consociata (E. A. Smith, 1885) and A. troscheli (Dunker, 1882) (Arcidae: Anadarinae) from Indian waters with notes on morpho-taxonomy of some related species from east coast of India, Records of the Zoological Survey of India 119 (1) : -

5. Anadara inaequivalvis ( Bruguière, 1789) ( Fig. 3 ; c - e)

1789. Arca inaequivalvis Bruguière ;

1965. Arca inaequivalvis : Kundu, 40

1998. Scapharca inaequivalvis : Poutiers, 152

2010. Anadara (Scapharca) inaequivalvis : Ramakrishna & Dey, 66

2017. Scapharca inaequivalvis : Subba Rao, 59

Material examined: 1ex, Puri (19°47.416’N and 085°49.346’E), 26-III-2007, coll. P. Yennawar, ( MARC / ZSI M3554 ) ; 3ex, Chandrabhaga (19°51.576’N and 084°06.409’E), 31-I-2008, coll. P. Yennawar, ( MARC / ZSI M3553 ) ; 2ex, Bokhali (21° 33.302’N and 088° 33.301’E), 06-II-2008, coll. P. Yennawar ( MARC / ZSI M469 ) ; 1ex, Gopalpur (19°15.449’N and 084°54.559’E), 3-II-2008, coll. P. Yennawar, ( MARC / ZSI M3074 ) ; 1ex, Digha (21°37.294’N and 087°31.338’E), 12-VII-2009, coll. P.C. Tudu ( MARC / ZSI M4153 ) ; 1ex, Udaypur (21°36.327’N and 087°28.529’E), 25-XI-2008, coll. P.C. Tudu ( MARC / ZSI M549 ) ; 1ex, Chandipur (21˚27’07.066” N and 087˚02’46.444” E), 1-X-2012, coll. P.C. Tudu ( MARC / ZSI M4152 ) ; 1ex, Paradip (20°15.115’N and 086°39.283’E), 20-III-2013, coll. A. Mohapatra ( MARC / ZSI M2992 ) ; 2ex, Chilka New Mouth (19° 39.486’N and 085° 31.050’E), 19-III-2013, coll. A. Mohapatra ( MARC / ZSI / M3646 ) ; 2 ex, Junput (21°43.143’N and 087°49.118’E), 13-VI-2013, coll. P.C. Tudu ( MARC / ZSI M3555 ) ; 13ex, Rameswaram (09°16.867’N and 079°18.879’E) 7-IX-2014, coll. P.C. Tudu ( MARC / ZSI M4141 ) ; 3ex, Tuticorin (08°47.575’N and 078°09.636’E) 9-IX-2014, coll. P.C. Tudu ( MARC / ZSI M4144 ) ; 8ex, Chennai (13˚07’25” N and 80˚17’50” E) 17- XII-2014, coll. P.C. Tudu ( MARC / ZSI M4139 ) .

Description: Shell of medium size (L up to 64.5mm & H up to 51mm), roughly quadrate in shape, inflated, inequilateral; with a broad and nearly straight margin; anterior margin slightly convex, arcuated ventrally and obliquely truncate posterior margin, with a postero-ventral fold; left valve distinctly overlapping the right valve ventrally and posteriorly ( Fig. 3 , d). Cardinal area rather long and narrow. Radial ribs low, flat and smooth; in the anterior filed of the left valve they are sometimes ornamented with crossings ridges; number of ribs 33-37; interspaces of the ribs smooth or covered by low cross

ridges on the bottom; width of interspaces as wide as the ribs, granulated on left valve. Beak somewhat broad, low, situated anteriorly from the middle of the shell. Ligamental area narrow. Hinge plate narrow, centre of series under the beak, the posterior series nearly twice as long as the anterior series. Periostracum well developed. Internal margin with strong crenulations corresponding with the external radial ribs; no byssal gape. Outside of shell white in colour covered with blackish brown periostracum, inner side also white.

Distribution: In India: all maritime states including Andaman and Nicobar Island (Ramakrishna and Dey, 2010); Elsewhere: Australia, Japan, Malaysia, Sri Lanka ( Poutiers, 1998), Singapore ( Tan & Woo, 2010), Vietnam ( Evseev and Lutaenko, 1998), Indo-Pacific ( Subba Rao et al., 1992), Central India Ocean, Western Pacific Ocean, Mediterranean and Black Sea ( Poutiers, 1998).

Remarks: Number radial ribs of this species is 30-36 ( Poutiers, 1998) and 32-35 ( Subba Rao et al., 1992), one of our specimens has total numbers ribs are 37 and other characters are similar with this species; so, we considered that, range of radial ribs of this species is 30-37.

Figures

Figure 3. a-b,A. ferriginea (Reeve, 1844), a- exterior of left valve, b- exterior of right valve; c-e, A. inaequivalvis (Bruguière, 1789); c-exterior of left valve, d- exterior of left valve & left valve overlapping the right valve along postero-ventral region, e- umbo; f-g, A. pilula (Reeve, 1843); f- exterior of right valve, g- interior of right valve.